The agency's investigators reported that the driver was having breakfast while he let Autopilot take over the driving; his hands were not on the steering wheel, and he did not brake prior to the crash.

This is not the first—and unfortunately probably won't be the last—case of drivers relying more extensively on Autopilot than Tesla expressly states they should.

The National Transportation Safety Board (NTSB) has determined that a man was having breakfast inside his Tesla when it crashed into a parked fire truck. The unidentified 47-year-old man, who ran into the back of a fire engine on Interstate 405 in Culver City, California, in January 2018, was using the car's Autopilot feature while he breakfasted on coffee and a bagel.

His hands were not on the steering wheel prior to the crash, nor did the 2014 Model S brake for the fire engine, which was stopped with lights flashing. He has not been identified in public records and is unknown if he will be criminally charged. The preliminary NTSB report released Tuesday said that because after the crash his coffee spilled and his bagel was smashed, the driver was not sure if his coffee or bagel was in his hand when the crash occurred. The agency does not assign blame in accident investigations.

NTSB report data concluded that the Tesla was driven on that day for about 30 miles over about 66 minutes, and during that time, Autopilot was engaged for 29 minutes and four seconds. "Hands were detected on the steering wheel for only 78 seconds," NTSB said.

The NTSB said Autopilot was on for the last 13 minutes and 48 seconds before the crash, of which time the driver had his hands on the wheel for a total of 51 seconds. "Place Hands on the Wheel" alerts came from the car's system four times, as did an audible warning. Cruise control was set for 80 mph. When the car in front changed lanes—presumably to move over for the fire truck—the man let his Tesla accelerate from 21 mph to 31 mph before hitting the back of the truck head-on, the report said. Fortunately there were no injuries to the "driver" or anyone in the crash zone.

A Tesla spokesperson issued a statement saying that "Tesla owners have driven billions of miles with Autopilot engaged, and data from our quarterly Vehicle Safety Report indicates that drivers using Autopilot remain safer than those operating without assistance." The EV maker also said that its driver-monitoring system "prohibits the use of Autopilot when warnings are ignored," although the NTSB report claims those warnings were issued in this case to no avail. Tesla also points out that it has updated its system since this 2018 accident, including "adjusting the time intervals between hands-on warnings and the conditions under which they're activated."